Hemithoracic radiation after extrapleural pneumonectomy for malignant pleural mesothelioma

The treatment of malignant pleural mesothelioma remains a therapeutic challenge, with median survival rates of about 12 months and local failure rates of up to 80%. Our institution recently published results showing that extrapleural pneumonectomy (EPP) followed by hemithoracic radiation yielded excellent local control. This paper reports our technique for high-dose hemithoracic radiation after EPP.

Between 1990 and 2001, 35 patients with malignant pleural mesothelioma were treated with EPP followed by hemithoracic radiation therapy (median dose: 54 Gy, range: 45-54 Gy) at Memorial Sloan-Kettering Cancer Center. EPP was defined as en bloc resection of the entire pleura, lung, and diaphragm with or without resection of the pericardium. The radiation therapy target volume was the entire hemithorax, including the pleural folds and the thoracotomy and chest tube incision sites. Patients were treated with a total dose of 5400 cGy delivered in 30 fractions of 180 cGy. Radiation therapy was well tolerated, and toxicity data are described.

Of the 35 patients analyzed, 29 patients were male, and 18 had right-sided tumors. Twenty-six had epithelioid histologies. UICC stage was I in 4, II in 11, III in 19, and IV in 1 patient. As shown by axial and sagittal isodose distributions, we were able to deliver adequate doses to the target volume while limiting dose to critical structures such as heart, spinal cord, liver, and stomach. The most common toxicities were RTOG Grades 1 and 2 nausea and vomiting, as well as lung, esophageal, and skin toxicities.

Extrapleural pneumonectomy followed by high-dose hemithoracic radiation therapy is a feasible treatment regimen that is well tolerated for patients with malignant mesothelioma. We have demonstrated adequate dose distributions, using a combined photon and electron technique with blocking of critical normal structures.